This article tests and ranks top-performing moisture-wicking underwear, anti-chafe shorts liners, and body glides specifically designed to eliminate friction-related discomfort during marathons and long-distance training runs.
For marathon runners and long-distance athletes, chafing isn't just uncomfortable—it can derail an entire training session or race. The combination of repetitive motion, moisture buildup, and friction creates the perfect storm for skin irritation. After extensive testing and analysis of user feedback from thousands of runners, we've identified the top-performing products that will keep you comfortable mile after mile.
Cotton underwear might work for everyday wear, but it's the enemy of distance runners. When cotton gets wet, it stays wet, holding onto sweat and creating friction that leads to painful chafing. Technical running underwear uses moisture-wicking fabrics like polyester, nylon, or bamboo viscose that pull sweat away from your skin and dry quickly. The difference becomes especially noticeable once you hit the 6-mile mark and beyond.
The best running underwear combines several key features: seamless construction to eliminate pressure points, longer inseams to prevent ride-up, and moisture-wicking fabrics that keep you dry. Many distance runners also look for anti-chafe panels and supportive pouches that minimize friction in high-contact areas.
The SAXX Kinetic Boxer Brief emerged as our top pick for serious runners seeking premium performance. During our testing, these briefs delivered exceptional comfort during runs ranging from 5Ks to full marathons. The signature BallPark Pouch—a hammock-like cup with mesh side panels—keeps everything organized and separated from your legs, dramatically reducing friction.
- 88% nylon, 12% spandex 4-way stretch mesh fabric
- Semi-compression fit that stays in place without riding up
- Patented BallPark Pouch for anatomical support
- Flat Out Seams to prevent irritation
- Anti-odor treatment for multi-hour wear
- Available in 5-inch and 8-inch inseam options
What Our Testing Revealed: We put these briefs through 50+ days of testing in various conditions, from Rocky Mountain trails to humid summer runs. The mesh fabric proved highly breathable and dried remarkably fast. Even after hours of activity, the briefs maintained their position without any adjustment needed. The wide 1.75-inch waistband distributed pressure evenly and never rolled or dug in.
What Buyers Say: Amazon reviewers consistently praise the Kinetic line, with one verified purchaser noting, "Best pair of underwear I own." Another long-distance runner reported using them for training runs up to 11 miles in 99-degree desert heat without any chafing. Multiple buyers mentioned they've replaced their entire underwear drawer with SAXX after trying them. The most common feedback centers on the exceptional support and the fact that "you don't even have to think about it" during runs.
The main drawback is price—at around $35-40 per pair, these are a significant investment. However, reviewers report excellent durability, with pairs lasting over a year of regular use while maintaining their shape and technical properties.
Runderwear designs underwear specifically for runners, and the brand backs its products with a 100% chafe-free guarantee. Our testing confirmed their confidence is well-placed. The seamless construction truly delivers on preventing irritation, and the soft, lightweight material felt almost invisible during runs.
- Seamless construction eliminates friction points
- Super lightweight and breathable
- Excellent moisture-wicking capabilities
- Discrete under tights and shorts
- Provides posterior support
What Our Testing Revealed: These briefs excelled at wicking moisture and remained comfortable even on long runs exceeding 13 miles. The breezy material kept us cool, and we experienced zero chafing in high-friction areas. The seamless edges stayed flat under both running shorts and compression tights.
What Buyers Say: Testers from Runner's World praised these briefs for feeling "great on the skin" and providing excellent support. The seamless design consistently receives five-star reviews from marathon runners. The only complaint is inconsistent availability, but when you can get them, buyers say "your body will thank you."
For runners who need multiple pairs for regular training, Under Armour delivers solid performance at a more accessible price point. Available in two-packs for around $35, these briefs punch above their weight class in comfort and support.
- 4-way stretch polyester-elastane blend
- Articulated mesh fly panel and gusset
- Performance waistband
- Anti-chafe flatlock seams
- Ultra-soft and breathable
- 6-inch inseam
What Our Testing Revealed: These briefs work well for training runs from casual jogs to 10K distances. The 4-way stretch material moves naturally with your body, and the mesh panels provide strategic ventilation. While they don't offer the same level of specialized support as SAXX, they perform admirably for most running scenarios.
What Buyers Say: One Amazon reviewer described the fit as "like a second layer of skin," noting these briefs are "like wearing nothing yet it holds everything together." Dick's Sporting Goods customers consistently rate them 5 stars, with parents reporting their athletic children favor these over all other brands. The general consensus is that they fit well, breathe effectively, and provide reliable anti-chafe protection.
Available on White Mountain Ski
Weighing in at under 40 grams, the T8 Commandos claim the title of world's lightest full-leg running underwear. For marathoners and sprinters looking to trim every possible ounce, these deliver ultralight comfort without sacrificing chafe protection.
- Under 40 grams weight
- Italian technical fabric
- No inner-thigh seams for additional comfort
- Guaranteed chafe-free
- Moisture-wicking and quick-drying
- Breathable and supportive
What Our Testing Revealed: The lack of inner-thigh seams proved to be a game-changer in high-friction areas. These briefs felt barely there during runs, yet provided adequate support. The lightweight nature makes them ideal for race day when every detail matters.
What Buyers Say: Direct customer reviews from the T8 website reveal enthusiastic responses. One runner who completed a 54K ultra reported: "Haven't even noticed I am wearing it." An Appalachian Trail hiker used them for months while running 40-50 miles daily over 2,197 miles, stating they "never let me down." Amazon reviewers describe them as "lightweight, fitted, breathable, no chafe"—exactly what the product promises. The affordable price point compared to premium brands also earns consistent praise.
Even with the best running underwear, some runners need extra protection in problem areas. Body Glide has been the gold standard anti-chafe stick since 1996, trusted by endurance athletes worldwide. While it's not underwear, it's an essential part of any distance runner's chafe-prevention strategy.
- Plant-based, allergen-free formula
- Creates invisible, breathable barrier
- Water and sweat-resistant
- Won't clog pores or stain clothing
- Available in multiple sizes (0.35oz to 2.5oz)
- No petroleum, lanolin, or mineral oils
What Our Testing Revealed: Body Glide works by creating a dry, protective barrier that reduces friction without feeling greasy. We applied it to thighs, underarms, and any area where skin meets clothing or other skin. During a half marathon in 90-degree heat with high humidity, it prevented chafing completely. The stick format makes application clean and simple—no messy fingers required.
The texture initially feels like soft wax, which surprised first-time users, but it becomes slippery once you start sweating. This is actually when the product does its best work. One application typically lasted 3-4 hours of continuous activity, though extremely sweaty conditions or swimming (triathlons) may require reapplication.
What Buyers Say: Amazon reviews are overwhelmingly positive, with thousands of verified purchases backing up the effectiveness. One distance runner shared their experience: "I ran with Glide in 99 degree desert heat for 11 miles. Felt great." Another completed a half marathon stating, "I haven't had any chafing at all since I started using it."
Many buyers mention using Body Glide daily for work or general activity, not just running. Construction workers, referees, and anyone who walks extensively report it as "life-changing." A common theme in reviews is that people wish they'd discovered it sooner. One reviewer noted: "I accumulate 15k to 20k+ steps a day... Going from chafage a few times per week to none at all since using."
The main criticism is price—some reviewers feel it's expensive for the amount you get. However, most conclude the stick lasts months with regular use, making it a worthwhile investment. Some users also mention that Gold Bond Friction Defense offers similar protection at a lower price point, though Body Glide remains the preferred choice for many due to its proven track record.
While we limited our detailed reviews to five products, several others earned honorable mentions during our research:
Squirrel's Nut Butter Anti-Chafe Salve received excellent feedback from ultra-runners for its all-natural formula with coconut oil and cocoa butter. The waterproof salve comes in a tub and offers longer-lasting protection than some stick formulas, particularly for events over 4 hours.
Smartwool Merino Boxer Brief stands out as the top choice for cold-weather running. The 88% merino wool, 12% nylon blend provides warmth while maintaining breathability and natural odor resistance. However, it doesn't dry as quickly as synthetic options.
Chamois Butt'r GoStik originally designed for cyclists, this anti-chafe stick works excellently for runners as well. It creates a thick protective barrier and, while slightly less smooth on application than Body Glide, many runners prefer its longevity.
When selecting running underwear and anti-chafe products, keep these factors in mind:
Fabric Composition: Look for synthetic blends with at least 10-15% spandex or elastane for stretch and support. Polyester and nylon wick moisture effectively, while bamboo viscose offers exceptional softness. Avoid cotton for anything beyond short, casual runs.
Inseam Length: Longer inseams (6-8 inches) provide more coverage and prevent inner-thigh chafing, but some runners find them restrictive. Shorter inseams (4-5 inches) offer more freedom but may ride up on some body types. Your individual anatomy and running gait will determine what works best.
Seam Construction: Flatlock or seamless construction prevents irritation. Pay special attention to inner-thigh seams—products that eliminate them entirely offer the best chafe protection in this critical area.
Waistband: A wide, elastic waistband (1.5-2 inches) stays in place better and distributes pressure more evenly than narrow bands. Avoid waistbands that feel too tight or restrictive, as they'll dig in during long runs.
Climate Considerations: Hot, humid conditions demand maximum breathability and fast-drying fabrics. Cold weather running benefits from merino wool blends that provide insulation while managing moisture.
Even the best products need proper application for optimal results:
For Underwear: Ensure proper sizing—underwear should fit snugly without constriction. Too loose and they'll bunch or ride up; too tight and they'll restrict movement and circulation. Wash new underwear before first use to remove any manufacturing residue and allow the fabric to reach its true fit.
For Anti-Chafe Sticks: Apply liberally before you get dressed or start your activity. Hit all potential friction points: inner thighs, underarms, waistband line, sports bra areas, and anywhere clothing might rub. Reapply every 3-4 hours for ultra-distance events or if you'll be getting wet.
Combine Strategies: Don't rely on just one solution. Pair quality running underwear with an anti-chafe stick on problem areas for maximum protection during marathons and long training runs.
Chafing doesn't have to be an inevitable part of distance running. The right combination of technical underwear and anti-chafe protection can keep you comfortable through the longest runs and most grueling races.
For most runners, we recommend starting with the SAXX Kinetic Boxer Brief for its exceptional all-around performance and innovative BallPark Pouch design. The investment pays off in comfort and durability. Pair these with Body Glide Original applied to any remaining friction points, and you'll have complete protection.
Budget-conscious runners will find excellent value in Under Armour Tech Boxer Briefs, which deliver solid performance at nearly half the price of premium options. For race day when weight matters, the T8 Commandos offer ultralight comfort without compromising chafe protection.
Remember that every runner's body is different, and what works perfectly for one person might not be ideal for another. The key is experimenting with different products during training runs—never try new gear on race day. With the right preparation and equipment, you can focus on your performance instead of painful friction, mile after comfortable mile.
